AbbVie has teamed up with Voyager Therapeutics on a tau protein-targeting program, paying $69 million upfront for an option on the Alzheimer’s disease candidate.
The duo says they will apply Voyager’s gene therapy vector expertise to develop a one-off Alzheimer’s treatment that uses adeno-associated virus (AAV) vectors to produce ‘vectorized’ anti-tau antibodies within the brain. According to AbbVie, that approach would have dosing advantages over current tau-targeting drugs in the industry’s pipeline that could translate into a higher chance of showing efficacy.
In addition to the upfront fee, the pharma company is pledging up to $155 million in potential preclinical and phase 1 opt-in payments, plus up to $895 million in development and regulatory milestones for each vectorized tau antibody compound. Voyager will fund the program through phase 1.
Tau has been something of an also-ran in Alzheimer’s drug development circles, crowded out by the sheer volume of drug candidates targeting amyloid beta that have so far failed to yield any effective therapies.
The protein—which aggregates to form characteristic neurofibrillary fibrils in the brains of patients with Alzheimer’s and other neurodegenerative diseases—has been pursued as a drug target by a select group of companies who say it leads directly to impaired brain function and neuronal cell loss.
They insist it could be a better target than amyloid as it tracks the progression of neurodegenerative diseases more closely while amyloid pathology is generally well established before cognitive symptoms are present.
AbbVie is prominent among the tau set with its phase 2 candidate ABBV-8E12 which is due for a data read-out in 2020 in Alzheimer’s, but it thinks there could be big advantages with a vectorized antibody approach as “one of the current limitations with the use of weekly or biweekly infusions of biologic therapies for neurodegenerative diseases is that only a small amount of drug is able to make its way into the brain.”
Like amyloid, tau is still a long way from proving its worth as a target in Alzheimer’s disease. One of the main proponents of the tau hypothesis—TauRx—has reported mixed data with its orally-active lead candidate LMTX. Nevertheless, TauRx is in the build-up phase to a larger study in the U.S., Canada and Europe as monotherapy and an add-on to current neurotransmitter-boosting drugs in mild Alzheimer’s disease patients. Eisai/Biogen, Bristol-Myers Squibb and Astellas have also said they have tau programs in the pipeline.